Apparatus and method for gas-liquid separation

ABSTRACT

A fuel bunkering apparatus shapes fluid flow in a flow shaping line preferably shaped to have a plurality of loops. Shaping the two-phase flow drives the heavier, denser fluids to the outside wall of the flow shaping line and allows the lighter, less dense fluids such as gas to occupy the inner wall of the flow shaping line. With the gas positioned on the inner wall, an exit port on the inner wall permits a majority, if not all, of the gas, along with a minimal amount of liquid, to be diverted to a conventional gas-liquid separator at a flow rate much lower than the total flow rate within the flow shaping line. The remaining liquid flow in the flow shaping line is subsequently introduced into an adjustable phase splitter to separate different liquid components from one another.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation patent application of U.S.patent application Ser. No. 15/138,085 filed on Apr. 25, 2016, which isa continuation patent application of U.S. patent application Ser. No.13/841,881, filed on Mar. 15, 2013, now U.S. Pat. No. 9,320,989 thebenefit of each of which is claimed and the disclosure of each of whichis incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention generally relates to the separation of componentsin a multi-phase flow stream. More specifically, it relates torestructuring flow regimes by a flow shaping apparatus so that themajority of a particular fluid component in a flow stream is located ina certain area of the flow stream, which allows for effective separationof the various fluid components.

BACKGROUND OF THE INVENTION

A gas-liquid two phase flow stream includes a mixture of differentfluids having different phases, such as air and water, steam and water,or oil and natural gas. Moreover, the liquid phase of a fluid flowstream may further comprise different liquid components, such as oil andwater. A gas-liquid two phase flow takes many different forms and may beclassified into various types of gas distribution within the liquid.These classifications are commonly called flow regimes or flow patternsand are illustrated in FIGS. 1A-1E. Bubble flow as illustrated in FIG.1A is typically a continuous distribution of liquid with a fairly evendispersion of bubbles in the liquid. Slug or plug flow as illustrated inFIG. 1B is a transition from bubble flow where the bubbles havecoalesced into larger bubbles with a size approaching the diameter ofthe tube. Churn flow as illustrated in FIG. 1C is a pattern where theslug flow bubbles have connected to one another. In annular flow asillustrated in FIG. 1D, liquid flows on the wall of the tube as a filmand the gas flows along the center of the tube. Finally, in wispyannular flow as illustrated in FIG. 1E, as the liquid flow rate isincreased, the concentration of drops in the gas core increases, leadingto the formation of large lumps or streaks of liquid.

It is often desirable to separate the gas and liquid components of afluid from one another to enable proper operation of systems, such ascertain types of liquid pumps. Conventional vertical or horizontalgas-liquid separators are available to separate gas from liquid.Conventional separators typically employ mechanical structures, whereinan incoming fluid strikes a diverting baffle which initiates primaryseparation between the gas and liquid components. Mesh pads or demisterpads are then used to further remove suspended liquid. The sizing of aseparator and the particular characteristics of the separator isdependent upon many factors, which may include, the flow rate of theliquid, the liquid density, the vapor density, the vapor velocity, andinlet pressure. Vertical separators are typically selected when thevapor/liquid ratio is high or the total flow rate is low. Horizontalseparators are typically preferred for low vapor/liquid ratio or forlarge volumes of total fluid.

One application of these types of separators is in oil and gas drillingoperations. Specifically, a mud-gas separator is used when a kick isexperienced in a wellbore during drilling operations. A kick is the flowof formation fluids into the wellbore during drilling operations. If akick is not quickly controlled, it can lead to a blow out. As part ofthe process for controlling a kick, the blow-out preventors areactivated to close the wellbore and wellbore fluids are slowlycirculated out of the wellbore while heavier drilling fluids are pumpedinto the wellbore. A mud gas separator is used to separate natural gasfrom drilling fluid as the wellbore fluid is circulated out of thewellbore. Often times, however, prior art separators, have limitedcapability to process flow streams with high volumes and/or high flowrates, such as those characteristic of wellbores.

Of course, separators are also used in the production of oil and gas toseparate natural gas from oil that is being produced. Additionally,there are many other applications that require the use of gas-liquidseparators. For example, when supplying fuel to ships, known asbunkering, air is often entrained in the fuel, causing an inaccuratemeasurement of the transferred fuel. Likewise, in oil production orproduction of other liquids, transferring or conveying a liquid mayresult in the liquid acquiring entrained gas during that process, aresult observed in pipelines with altered terrains. In this regard,entrained gasses can prevent the accurate measurement of a liquidproduct, whether it is fuel transferred during bunkering or a liquidflowing in a pipeline.

SUMMARY OF THE INVENTION

One aspect of the invention relates to shaping multi-phase mixed flowusing a curvilinear flow line formed in multiple loops or coils prior toseparation of a fluid component from the flow path. Shaping themulti-phase flow into a curvilinear path will allow centrifugal force tomore readily force the heavier, denser liquid to the outside or outerdiameter wall of the flow shaping line in the curved path and allow thelighter, less dense vapor or gas to flow along the inside or innerdiameter wall of the flow shaping line. In certain embodiments, once aflow regime has been restructured within the flow line, the flowcomponent collected adjacent a particular wall of the line can beremoved. For example, in flow streams characterized by a larger liquidcomponent, the gas component of a liquid-gas flow stream will collectalong the inner diameter wall of the curved flow shaping line, where thegas can be drawn or driven into an exit port located on the inner wall,thereby permitting a majority, if not all, of the gas, along with a lowamount of liquid, to be sent to a conventional gas-liquid separator. Theseparated fluid will have a comparatively higher ratio of gas to liquidthan the primary flow stream in the flow line, but will pass into theconventional gas separator at a flow rate much lower than the total flowrate within the flow shaping line. This permits for efficient separationof the gas from the liquid with the use of a smaller, more economicalconventional gas-liquid separator than what would have been required forthe full flow stream and/or higher flow rates.

In certain embodiments, a curvilinear flow line, whether in the form ofa single loop or multiple loops, may be utilized in conjunction with asensor for controlling an adjustable valve. In each case of multipleloops, the loops in the flow line permit an extended residence time of aflow stream through the system. A sensor disposed along the flow path isutilized to estimate a property of the flow 12, such as for example, thepercentage or “cut” of one or more components of the flow steam. Theadjustable valve is positioned sufficiently downstream so that the valvecan be timely adjusted based on the measurement from the sensor. Forexample, a sensor measuring cut can be utilized to adjust the positionof a weir plate in the flow stream, thereby increasing or decreasing theamount of fluid separated from the flow stream. Although the sensors asdescribed herein will be primarily described as measuring the cut, othertypes of sensors may also be utilized. Likewise, the type of cut sensorsare not limited to a particular type, but may include the non-limitingexamples of interface meters; optics or capacitance sensors. Theextended residence time of the flow stream in the multi-loop systempermits the valve to be adjusted once the cut is determined, therebyenhancing separation of fluid components once the flow stream has beenrestructured in accordance with the invention. The adjustable valve maybe, for example, be a weir plate, foil or similar structure that can beused to draw off or separate one component of the flow stream. Othertypes of adjustable valves may also be utilized.

In certain embodiments of a multi-loop system, the primary diameter ofone or more loops or coils generally disposed along an axis may bealtered along the length of the axis to control the flow rate throughthe system. In certain embodiments, the flow line will include aplurality of loops formed along an axis, with each successive loophaving a smaller primary diameter than the preceding loop, such that thevelocity of the flow stream within the flow line increases along theaxis while maintaining flow regime separation. Likewise, in certainembodiments, the flow line will include a plurality of loops formedalong an axis, with each successive loop having a larger primarydiameter than the preceding loop, such that the velocity of the flowstream within the flow line decreases along the axis.

In certain embodiments of a multi-loop system, two sets of loops orcoils may be utilized along a flow path. The first set of loops willfunction to separate a component, such as gas, as described above. Thesecond set of loops functions to address any gas that remains in theflow stream. In certain embodiments, prior to introduction of the flowstream into the second set of loops, the flow stream may be agitated soas to thereafter enhance flow regime reshaping as described above.

Additionally, a fluid guiding surface may be placed on the inner wall ofthe flow shaping line at the exit port to further aid in directing thegas to flow to the conventional gas separator.

Furthermore, the liquid return from the conventional gas-liquidseparator may be arranged in close downstream proximity to the exit porton the inner wall of the flow shaping line. The close proximity of theliquid return and the exit port allows the use of a venturi, nozzle orother restriction located adjacent the liquid return in the flow shapingline just downstream of the exit port. The venturi, nozzle or otherrestriction accelerates the velocity of the liquid in flow shaping lineas it flows across the exit port. This acceleration of the liquid helpsto pull the liquid out of the conventional gas-liquid separator. Inaddition, the acceleration of the liquid within the flow shaping linehelps to prevent any solids that may be present in the gas-liquid flowfrom entering the exit port and it helps to lower the amount of liquidthat enters the exit port and thus enters the conventional separator.

In certain embodiments, a heater may be disposed along a flow streamprior to flow regime reshaping in order to cause a phase change of atleast a portion of the fluid within the flow stream. For example,certain liquid hydrocarbons in flow stream may be converted to gas underan applied heat in order to enhance separation of the hydrocarbon fromthe flow steam as described above. Such a heater may be utilized withcurvilinear flow line having either single and multi-loops.

Likewise, in certain embodiments, a curvilinear flow line having eithersingle and multi-loops may be utilized in conjunction with aliquid-liquid phase separator. The liquid-liquid phase separator ispreferably deployed down stream of the exit port and is disposed toseparate different density liquids from one another. In certainembodiments, the liquid-liquid phase separator may be adjustable andutilized in conjunction with a sensor. The sensor is disposed along theflow path downstream of the gas exit port and is utilized to estimatethe percentage or “cut” of various liquids remaining in the flow steam.The phase separator can be adjusted based on the cut. The phaseseparator may include, for example, an adjustable weir plate, adjustablefoil, adjustable valve or similar adjustable mechanism. In oneembodiment, the phase separator may include an adjustable valve in theform of rotatable ball having two flow passages therethrough. Rotationof the ball adjust the positions of the flow passages relative to theliquid-liquid flow stream, exposing more or less of a particular passageto the flow steam. Other types of adjustable valves may also beutilized.

In another embodiment of the invention particularly suited for flowstreams with a high gas content, i.e., “wet gas”, a flow channel isformed along at least a portion of the inner diameter wall of acurvilinear flow line as described herein. The liquid within the wet gaswill collect in the flow channel and can be drained off from the primaryflow stream.

In another embodiment of the invention, the gas-liquid separatorincludes a variable position gas control valve that maintains levelcontrol of a vessel and establishes a constant flow pressure throughoutthe system.

The invention therefore allows a multi-phase fluid to be effectivelyseparated with the use of a smaller conventional separator than waspreviously possible. The invention accomplishes this without usingadditional complex mechanical devices and thus will operate efficientlyand reliably.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present disclosure and advantagesthereof may be acquired by referring to the following description takenin conjunction with the accompanying figures, wherein:

FIGS. 1A-1E illustrate a cross-sectional view of various flow regimes oftwo phase gas-liquid flow.

FIG. 2 illustrates a cross-sectional view of an embodiment of separationapparatus with a flow regime modification loop/coil and a liquid-liquidphase splitter.

FIG. 3 illustrates an elevation view of the embodiment of the separationapparatus with a plurality of flow regime modification loops/coils ofdescending cross-sectional diameter.

FIG. 4 illustrates an elevation view of the embodiment of the separationapparatus with a plurality of flow regime modification loops/coilshaving successively decreasing diameters and a liquid-liquid phaseseparator.

FIG. 5 illustrates an elevation view of the embodiment of the separationapparatus with a plurality of flow regime modification loops/coilshaving substantially the same diameters and a liquid-liquid phaseseparator.

FIG. 6a illustrates an elevation view of the embodiment of theseparation apparatus with two sets of flow regime modificationloops/coils of FIG. 4.

FIG. 6b illustrates an elevation view of the embodiment of theseparation apparatus with two sets of flow regime modificationloops/coils of FIG. 5.

FIG. 7 is an elevation view of a multi-phase flow separation apparatusutilizing two sets of loops/coils of FIG. 4, arranged in series.

FIG. 8 illustrates a cross-sectional view of a flow regime modificationloop/coil for wet gas processing.

FIG. 9 illustrates a cross-sectional view of another embodiment of aliquid-liquid phase splitter with an adjustable valve.

FIG. 10 illustrates a cross-sectional view of a gas control valve in agas separation tank.

FIG. 11 illustrates an elevation view of another embodiment ofseparation apparatus deployed in oil and gas drilling operations.

FIG. 12 illustrates an elevation view of another embodiment ofseparation apparatus deployed in fuel bunkering operations.

DETAILED DESCRIPTION

In the detailed description of the invention, like numerals are employedto designate like parts throughout. Various items of equipment, such aspipes, valves, pumps, fasteners, fittings, etc., may be omitted tosimplify the description. However, those skilled in the art will realizethat such conventional equipment can be employed as desired.

FIG. 2 illustrates a cross-sectional view of an embodiment of aseparation apparatus 10. In an exemplary embodiment, the separationapparatus 10 is in fluid communication with a main flow line 15 in whicha multi-phase flow 12 is traveling. The multi-phase flow 12 could be anytype of multiphase gas-liquid flow regime or flow pattern, such as, forexample, bubble flow, slug or plug flow, churn flow, annular flow orwispy annular flow. Moreover, the multi-phase flow may include twocomponents within a single phase, such as water and oil within theliquid phase. The multi-phase flow 12 within main line 15 is directedinto a curvilinear flow path 16 in a flow shaping line 17. In certainembodiments, such as is illustrated in FIG. 2, the curvilinear flow path16 is substantially in the form of a loop having a circular shape,although the curvilinear flow path may have other curvilinear shapes. Inany event, the curvilinear flow path 16 of flow shaping line 17 createsan increased distribution of a first phase 22, such as gas, along theinner wall 24 of the flow shaping line 17. The increased distribution ofthis first phase 22 along the inner wall 24 of the flow shaping line 17results in part by the relatively heavier and denser second phase 18,such as a liquid, of flow 12 being forced to the outer wall 20 of theflow shaping line 17 due to centrifugal force of curvilinear flow path16, while the lighter first phase 22 is driven to the inner wall 24. Theflow shaping line 17 may be disposed in any orientation, includingsubstantially in a vertical plane or a horizontal plane. In embodimentswith a vertical or partly vertical orientation of the flow shaping line17, gravitational effects may also aid in increasing the distribution ofthe first phase 22 on the inner wall 24 of the flow shaping line 17.

As the multi-phase flow 12 continues to travel through the curvilinearflow path 16 of flow shaping line 17, the multi-phase flow 12 forms aflow path that exhibits a high concentration of gas 22 along the innerwall 24 of the flow shaping line 17. In the embodiment shown in FIG. 2,at location 26, which is approximately 315 degrees around shaping line17 (or 45 degrees from the vertical), the separation of gas 22 fromliquid 18 has reached a degree that gas 22 primarily occupies the spaceadjacent the inner wall 24 of the flow shaping line 17. As seen in FIG.3, which is a cross section 3-3 of the flow shaping line 17 andmulti-phase flow 12 at location 26, the gas 22 occupies mainly the innerwall 24 of the circular flow path 16 of the flow shaping line 17 whilethe liquid 18 primarily travels along the outer wall 20.

With gas-liquid flow 12 forming a more stratified flow regime, or atleast the distribution or volume of gas near the inner wall 24 of theflow shaping line 17 has increased at the point of location 26, the gas22 may be effectively bled off from the gas-liquid flow 12 at an outletport 28 positioned along the inner wall 24 of the flow shaping line 17,preferably along a curvilinear portion of flow shaping line 17. In thisregard, although outlet port 28 may be positioned anywhere along flowpath 16, it is preferably selected to be at a point where substantialseparation of gas from liquid has occurred. Thus, in one preferredembodiment, the outlet port 28 is downstream of location 26. At about alocation 26, which is approximately at an angle of approximately 45degrees from a vertical axis 74 or otherwise, approximately 315 degreesabout a circular flow path, it has been found that the concentration,separation or stratification of the gas 22 from the liquid 18 is at apoint that gas 22 occupies a greater volume of space adjacent the innerwall 24 of the main line 15 than liquid 18. In other embodiments, theoutlet port 28 may be located between generally 45 degrees from thevertical and generally zero degrees with the vertical. While location 26is illustrated at approximately 315 degrees around flow shaping line 17and has been found to be a point where a substantial volume of gas hasbeen driven to inner wall 24, location 26 is used for illustrativepurposes only. In this regard, in configurations with multiple loopsformed by flow shaping line 17, the outlet port 28 may be disposed alongan inner wall of any one of the loops, including the first loop, thelast loop or an intermediate loop.

In an exemplary embodiment, a fluid guiding surface 30 is located at theoutlet port 28. In certain embodiments, a fluid guiding surface 30 a maybe located on the inside diameter 32 of the inner wall 24 of the flowshaping line 17 upstream of the outlet port 28. The fluid guidingsurface 30 includes a downstream end 36 that curves around the corner 37located at the junction of the outlet port 28 and the flow shaping line17. The gas 22 follows the contour of the fluid guiding surface 30 a andthe gas 22 will follow the curve of the downstream end 36 into theoutlet port 28. In another embodiment, a fluid guiding surface 30 b maycomprise a weir plate, foil or similar separation mechanism disposed todirect gas 22 into outlet port 28. The fluid guiding surface 30 bfunctions to guide the gas 22 into the outlet port 28. In certainembodiments, fluid guiding surface 30 b is adjustable in order to adjustthe position of fluid guiding surface 30 b, and hence, the first phasecut removed from flow stream 12. A sensor 34 may be disposed to operatein conjunction with and control adjustable fluid guiding surface 30 bbased on a measured property of the flow stream 12, such as cut.Although sensor 34 may be located anywhere along main line 15 or flowshaping line 17, it has been found that sensor 34 is preferablyseparated a sufficient distance from outlet port 28 to permit theposition of adjustable fluid guiding surface 30 b to be adjusted oncethe cut of flow 12 has been determined. Likewise, in certainembodiments, sensor 34 is disposed along flow shaping line 17 at a pointwhere substantial phase separation has taken place, such as at 26,thereby increasing the accuracy of sensor 34.

An amount of liquid 18′ from the gas-liquid flow 12 will also be carriedinto the outlet port 28 thus forming a new gas-liquid flow 40 whichincludes a much lower percentage of liquid 18′ compared to the liquid 18in gas-liquid flow 12. The new gas-liquid flow 40 from outlet port 28 isthen directed into a conventional gas-liquid separator 38, as shown inFIG. 2, for further separation of the gas and liquid. Outlet port 28 isconnected to the conventional gas-liquid separator by separator inletline 33. The gas-liquid separator 38 contains a gas exit 39 to permitremoval of gas 22 separated from flow stream 12. The gas-liquidseparator 38 also contains a liquid exit 41. In certain embodiments,liquid exit 41 that may be in fluid communication, via a line 44, withflow shaping line 17 or a subsequent flow line 43 disposed at the end ofthe flow shaping line 17. Those skilled in the art will appreciate thatseparation apparatus 10 is shown as integrated with gas liquid separator38, but can be a completely separate structure.

In an exemplary embodiment, the liquid inlet port 42 is in closedownstream proximity to outlet port 28 with a venture or similarrestriction 46 formed therebetween along the flow path of liquid 18flow. The restriction 46 accelerates the velocity of the liquid 18 as itflows across the liquid inlet port 42. This acceleration of liquid 18lowers the pressure of the liquid 18 flow in the primary flow path belowthat of the liquid 18′ in line 44, thereby drawing liquid 18′ out of theconventional gas-liquid separator 38. In addition, the acceleration ofthe liquid 18 facilitates separation of gas from liquid within flowshaping line 17, minimizes the likelihood that any solids present in thegas-liquid flow 12 will enter outlet port 28, and minimizes the amountof liquid 18 that enters the outlet port 28.

In certain preferred embodiments, venturi 46 is adjustable, permittingthe velocity of the flow therethrough, and hence the pressure dropacross the venturi 46, to be adjusted in order to control the amount ofliquid 18′ drawn from conventional gas-liquid separator 38. This inturn, permits the pressure of the gas within gas-liquid separator 38, aswell as the proportional amounts of liquid and gas therein, to becontrolled. This is particularly desirable when gas void fraction toliquid is a higher percentile. To eliminate bypass of gas that mightpass extraction point 28.

As mentioned above, the efficient first step in the separation of thegas 22 from the liquid 18 significantly decreases the amount of liquid18 entering the conventional gas-liquid separator 38. This allows forthe use of much smaller size conventional gas-liquid separators thanwould have previously been possible for a given flow rate and/or flowvolume.

While circular flow path 16 is shown as positioned in a vertical plane,in another embodiment the circular flow path 16 could be in a horizontalplane (see FIG. 12) or in a plane with an inclination between horizontaland vertical.

In certain embodiments, as further illustrated in FIG. 2, a phasesplitter 50 is in fluid communication with flow shaping line 17 toreceive the liquid 18 flow therefrom. Phase splitter 50 may be in directfluid communication with flow shaping line 17 or may be in communicationwith a flow line 43 disposed between the phase splitter 50 and flowshaping line 17. In this regard, a flow line 43 may be utilized tostratify multiple liquid components within liquid 18 by stabilizing thefluid flow. For example, flow line 43 may be horizontally disposed sothat liquids 18 a with a first density, such as oil, separate fromliquids 18 b with a second density, such as water, by virtue ofgravitational effects acting thereon. Alternatively, additional loops inflow shaping line 17 may be utilized to stratify the liquid components18 a, 18 b.

Phase splitter 50 includes a housing having a liquid inlet 52 forreceipt of liquid 18, as well as a first liquid outlet 54 and a secondliquid outlet 56. A weir plate, foil or similar separation mechanism 58is disposed within phase splitter 50 to direct a portion of the liquid18 into first outlet 54 and allow a portion of the liquid 18 to passinto second outlet 56. For example, weir plate 58 may be disposed todirect a substantial portion of liquid component 18 b into first outlet54, while allowing liquid component 18 a to pass over weir plate 58 intosecond outlet 56. In this way, separation apparatus 10 may be used notonly to separate gas from liquid, but also to separate liquid fromliquid in instances where gas and multiple liquids comprise flow stream12.

In certain embodiments, separation mechanism 58 may be adjustable inorder to adjust the position of separation mechanism 58, and hence, thecut of liquid removed from liquid 18. Non-limiting examples of anadjustable separation mechanism 58 include an adjustable valve,adjustable weir plate or adjustable foil. A sensor 60 may be disposed towork in conjunction with and control an adjustable separation mechanism58 based on a measured property of liquid 18, such a cut. Althoughsensor 60 may be located anywhere along main line 15 or flow shapingline 17 or line 43, it has been found that sensor 60 is preferablyseparated a sufficient distance from separation mechanism 58 to permitthe position of separation mechanism 58 to be adjusted once the propertyof flow 12 has been determined. Likewise, in certain embodiments, sensor60 is disposed along flow shaping line 17 or line 43 at a point wheresubstantial liquid stratification has taken place, thereby increasingthe accuracy of sensor 60. In certain embodiments, sensor 34 and sensor60 may be a single sensor utilized for multiple functions, such as toidentify the cut of gas, a first liquid and a second liquid in flow 12.

Turning to FIG. 4, other embodiments of the invention are illustrated.In certain embodiments, the curvilinear flow path 16 is substantially inthe form of a plurality of loops L₁ . . . L_(i), each loop characterizedby a diameter D₁ . . . D_(i) that together comprise flow shaping line17. The loops L are disposed along an axis 62. In certain embodiments,the diameter D of the loops L may remain substantially constant alongthe length of axis 62, while in other embodiments, the diameter of theloops may increase or decrease, either randomly or successively. In theillustrated embodiment, the diameter D of successive loops decreasealong the length of the flow shaping line 17 from the first end 64 tothe second end 66 of flow shaping line 17.

The plurality of loops L may be provided to develop the increasedconcentration of the gas 22 on the inner wall 24 of the flow shapingline 17. Moreover, the plurality of loops L increases the residence timeof the flow 12 or liquid 18 through flow shaping line 17. It may bedesirable, for example, to increase residence time of the flow 12 orliquid 18 through the system 10 in order to measure the flow or liquidwith sensors, such as the sensors 34, 60 described above, and makeadjustments to adjustable mechanisms 30 b, 58 based on the measurementsprior to the flow 12 or liquid 18 reaching the adjustable mechanism. Forexample, the phase splitter 50 may be adjusted to separate liquid 18into multiple phases, or the foil 30 b may be adjusted to separate gas22 from flow 12.

In this same vein, it may be desirable to alter the rate of the flow 12or liquid 18 through system 10. This is achieved by increasing ordecreasing the diameter D of the loops L to achieve a particular flowrate for a particular deployment of system 10. In one embodiment, forexample, the diameter D of the loops L is decreased, resulting in anincrease in velocity of the flow 12 from first end 64 to second end 66which thereby results in greater centrifugal force and increasedconcentration of the gas 22 on the inner wall 24 of the flow shapingline 17.

Sensors 34 and 60 may be disposed anywhere along the flow path of system10 as desired. Likewise, outlet 28 along inner wall 24 may be positionedanywhere along flow shaping line 17, the position being selected asdesired based on the components of flow 12. Thus, outlet 28 may bepositioned in the first loop L1 or a subsequent loop L, as illustrated.Likewise, liquid inlet port 42 may be in fluid communication with flowshaping line 17 or line 43 at any point in order to reintroduce liquid18′ from separator 38 back into the main liquid 18 stream.

FIG. 4 also illustrates an optional phase splitter 50 utilized inconjunction with the flow shaping line 17 shown. FIG. 4 also illustratesan optional heater 68 utilized in conjunction with flow shaping line 17.Heater 68 is particularly useful when the flow 12 includes certainliquid components which are desirably removed as a gas utilizing system10. For example, certain liquid hydrocarbons, such as methane or gassesthat might move from liquid to gas at different flash or boilingtemperatures, may be present in a flow 12 recovered from a wellbore (seeFIG. 11). Rather than recover the hydrocarbons as liquids, it may bedesirable to heat the flow 12 using heater 68 to a temperature where thehydrocarbons convert to gas 22, after which the hydrocarbon gas 22 canbe removed through outlet port 28 and separator 38.

FIG. 5 illustrates the system 10 shown in FIG. 4, but with all of theloop diameters D approximately the same dimension. In the embodiment ofFIG. 5, residence time may be maintained while the adjustable mechanism58 in phase splitter 50 is adjusted based on one of the sensors 34, 60.

FIG. 6a illustrates the multi-loop system 10 shown in FIG. 4, but withtwo sets of loops. In this case, a first flow shaping line 17 a and asecond flow shaping line 17 b are illustrated. Flow shaping lines 17 a,17 b each have multiple loops L, which loops L may have substantiallythe same diameter D or successively increasing or decreasing diametersD. The flow can be divided and processed in parallel so that portions ofthe flow stream are simultaneously processed as described above, afterwhich, the liquid from each set of loops can be recombined and directedtowards outlet 72. Multiple sets of loops arranged in parallel areparticularly useful in cases of large flow volume

The system 10 of FIG. 6b is the same as that of FIG. 6a , but the loopsL have substantially the same diameter D. The system of FIG. 6b may alsobe used in conjunction with a heater 68, cut sensors and adjustable cutmechanism 30 b as described herein.

With reference to FIG. 7, system 10 includes two sets of loops arrangedin series. In this case, a first flow shaping line 17 c and a secondflow shaping line 17 d are illustrated. Flow shaping lines 17 c, 17 deach have multiple loops L, which loops L may have substantially thesame diameter D or successively increasing or decreasing diameters D. Inthe illustrated embodiment, in each set of loops, the loops L have agradually decreasing diameter along the curvilinear flow path 16. Aheater 68 may be disposed to convert part of the flow 12 to a gaseousphase. Outlet port 28 to line 33 leading to separator 38 is positionedalong the flow shaping line 17 c at a point where it is expected asubstantial amount of phase separation to have occurred after passingthrough at least a portion of the curvilinear flow path 176. A sensor 34is positioned in order to measure a property of the flow 12. Sensor 34is spaced apart along flow shaping line 17 c a sufficient distance toallow the flow 12 to have a residence time in the loops prior toreaching outlet port 28 positioned on inner wall 24, thereby permittingan adjustable separation mechanism, such as 30 b shown in FIG. 2, to beadjusted accordingly. First flow shaping line 17 c is intended to removea large portion of the gas 22 that comprises fluid flow 12. Thereafter,the liquid 18 passes through line 43 and into the second flow shapingline 17 d to remove remaining gas that may be within the flow exitingthe first flow shaping line 17 c. Again, a sensor 34 may be utilized inconjunction with an adjustable separation mechanism adjacent outlet port28 of second flow shaping line 17 d.

In one configuration of the system 10 shown in FIG. 7, flow shapinglines 17 d operates as describe in FIG. 2, passing a liquid comprised ofsubstantially first and second liquid components 18 a, 18 b into phasesplitter 50. A sensor 60 may be disposed along flow shaping line 17 d tocontrol an adjustment mechanism 58 disposed within phase splitter 50.

Multiple sets of loops are particularly useful in cases of large flowvolume. The flow can be divided and processed in parallel so thatportions of the flow stream are simultaneously processed as describedabove, after which, the liquid from each set of loops can be recombinedand directed towards outlet 72.

Turning to FIG. 8, another embodiment of a flow shaping line 17 isillustrated. In this embodiment, flow shaping line 17 is shown in crosssection and includes a channel 74 formed along the inner wall 24 of atleast a portion of the curvilinear flow path 16. Channel 74 may beutilized in any configuration of a flow shaping line 17 having acurvilinear portion, including flow shaping line formed in both singleloop and multiple loop arrangements. It has been found that such systems10 having a channel 74 are particularly effective in multi-phase flowregimes with a high gas to liquid content. In other words, flow 12 iscomprised primarily of gas 22, with a relative low amount of liquid 18suspended therein. As flow 12 follows the curvilinear shape of flowshaping line 17, the liquid 18 will become trapped within channel 74 andcan be drained off through an outlet port 28 disposed along channel 74.Thereafter, the separated liquid may be introduced into a secondcurvilinear flow shaping line 17 without a channel xx to permitseparation of gas from liquid as depicted and discussed in the foregoingembodiments and illustrations.

FIG. 9 illustrates one embodiment of an adjustable separation mechanism58 for use in phase splitter 50. Adjustable separation mechanism 58 is aball valve 76 having a ball 78 rotatably mounted in a ball seat 80carried within a phase splitter housing 82. Ball 78 includes a firstpassageway 84 having an inlet 86 and an outlet 88, as well as a secondpassageway 90 having an inlet 92 and an outlet 94. Passageways 84 and 90are formed in ball 78 so that inlets 86, 92 are adjacent one another,while outlets 88, 94 are spaced apart from one another. In oneembodiment, passageways 84, 90 converge at inlets 86, 92 so that aportion of ball 78 defining passageways 84, 90 forms an edge 96. Aspreviously described, phase splitter 50 includes a liquid inlet 52, afirst outlet 54 and a second outlet 56. Ball valve 76 is disposed inseat 80 so that the inlets 86, 92 are adjacent fluid inlet 52, firstball outlet 88 is in fluid communication with first outlet 54 and secondball outlet 94 is in fluid communication with outlet 56. In a preferredembodiment, edge 96 is positioned adjacent inlet 52. Rotation of ball 78thereby adjusts the position of edge 96 in liquid stream 18 as liquidstream 18 flows across edge 96. In this way, valve 76 can be adjusted toalter the cut from liquid steam 18 such that a portion of the liquid 18a flows through first passageway 84 and a portion of the liquid 18 bflows through the second passageway 90. Persons of ordinary skill in theart will understand that passageways 84, 90, and their respective inlets86, 92 may be sized so that valve 76 may also be adjusted to divert allof liquid 18 flowing though inlet 52 into either first or secondpassageway 84, 90, as desired.

With reference to FIG. 10, a variable position gas control valve 98 isplaced on the gas outlet 39 side of the two-phase separation vessel 38.The liquid outlet 41 is unregulated and allowed to drain. As gas isallowed to escape the level increases in the vessel and when gas is notallowed to escape the level decreases. The incoming flow 40 iscontrolled and maintained at a specific level in separator 38 in orderto stabilize the pressure therein so that liquid full flow bypass can bemaintained without peeks or fluctuations in flow rate.

As described above, one application for the invention is to protectagainst “kicks,” such as in subsea applications, by circulating outhydrocarbon gas at the seabed floor before the gas is able to rise up toa drilling rig. Referring to FIG. 11, in an exemplary embodiment,illustrated is a conventional sub-sea blow out preventer 150 located onthe seafloor 152. A marine riser 154 extends from the blow out preventer150 and within the riser is a drillpipe 156. One embodiment of theseparation apparatus 110 is positioned along drillpipe 156, preferablyadjacent the blow out preventer 150. In normal drilling operations,drilling fluid 158 is pumped down the drillpipe 156 from the drillingrig 157 and returns to the drilling rig 157 via annulus 160 formedbetween the drillpipe 156 and the riser 154. If a “kick” is detected,such as by cut or similar sensors described herein, inlet annulus valve162 is activated, diverting returning drilling fluid 158 from annulus160 into the flow shaping line 117. Flow shaping line may have one ormultiple sets of coils. In the case of a single set of coils, flowshaping line is preferably arranged so that successive loops L along theline 117 having a decreasing diameter. In the case of multiple sets ofcoils, the flow shaping lines 117 may be arranged in parallel. Naturalgas entrained in drilling fluid 158 from the “kick” is then separatedfrom the drilling fluid 158 by the separation apparatus 110 as describedabove. Specifically, gas will exit flow shaping line 117 into aseparator 138. The natural gas then exits the gas-liquid separator 138at the gas exit 139 and may flow up riser 166 to the drilling rig whereit may be safely handled, for example, sent to a flare boom of thedrilling rig 157, or compressed and re-distributed (also not shown).

Following separation of natural gas from the recovered drilling fluid158 by separation apparatus 110, the drilling fluid 158 is re-introducedinto the annulus 160 at an exit annulus valve 168. In comparison withthe usual procedure of handling a kick, the use of an embodiment of thisinvention allows for full flow or circulation of the drilling fluidwithout having to choke down the flow or operate the blow out preventervalves.

In another embodiment, the inlet annulus valves 162 or exit annulusvalves 168 can be eliminated, bypassed or operated so that the upwardflowing drilling fluid 158 continually flows through the separationapparatus 110. Compared to the usual procedure on a drilling rig whenthere is a kick of choking the flow of the drilling fluid and being ableto only send a portion of the flow to the mud-gas separator located onthe drilling rig, an embodiment of the present invention allows the fullflow of the drilling fluid to be handled by the separation apparatus 110and the separation safely takes place near the seafloor.

In one embodiment, flow shaping line 117 may comprise multiple loops ofdecreasing diameter as described above and illustrated in FIG. 11. Inother embodiments, flow shaping line 117 may comprise a single loop ormultiple loops of substantially the same diameter, but utilized inconjunction with a heater 68 to convert certain hydrocarbons to gasand/or a sensor 34 utilized in conjunction with an adjustable cutmechanism 30 b (see FIG. 2), such as a foil, weir plate or valve.

In another embodiment illustrated in FIG. 11, a separation apparatus 210having a flow shaping line 211 is utilized in conjunction with drillingand a hydrocarbon recovery system near the ground or water surface 212.A fluid flow (such as fluid flow 12 in FIG. 2) from a wellbore 216 isdirected into flow shaping line 211 positioned adjacent a drilling rig157. In normal drilling operations, drilling fluid 158 is pumped down adrillpipe 156 from the drilling rig 157 and returns to the drilling rig157 via annulus 160 formed between the drillpipe 156 and a pipe 154,such as a riser in the case of marine drilling operations or a wellcasing in the case of land drilling operations. The recovered drillingfluid 158 from annulus 160 is directed into the flow shaping line 211.Preferably, drilling mud and cuttings are first removed from the flow214 using various systems 215 known in the industry before introductioninto flow shaping line 211. Natural gas entrained in drilling fluid 158is then separated from the drilling fluid 158 by the separationapparatus 210 as described above. Specifically, gas will exit flowshaping line 211 into a separator 238. The natural gas 164 exits thegas-liquid separator 238 at the gas exit 239.

In one embodiment, flow shaping line 211 may comprise multiple loops ofdecreasing diameter as described above and illustrated in FIG. 4. Inother embodiments, flow shaping line 211 may comprise a single loop ormultiple loops of substantially the same diameter, but utilized inconjunction with a heater 68 to convert certain hydrocarbons to gasand/or a sensor 34 utilized in conjunction with an adjustable cutmechanism, such as a foil, weir plate or valve. Moreover, separationapparatus 210 may include a phase splitter 220 in fluid communicationwith line 211 and disposed to separate liquid components as describedabove.

In another embodiment illustrated in FIG. 12, a multi-phase flowseparation apparatus 310 can be utilized in bunkering operations tosupply ships with fuel. Bunker fuel generally refers to any type of fueloil used aboard ships. Bunker fuels are delivered to commercial shipsvia bunker barges, which often hold the bunker fuel in large tanks 312.The practice of delivering bunker fuels is commonly referred to as“bunkering”, as such bunker barges can also be known as bunkeringbarges. The bunker fuel is typically pumped from the barge's tanks 312to the tanks 314 on commercial ships. At times, bunker fuels may betransferred between bunker barges. In any event, the pumping of fuel inbunkering operations, especially as the vessels containing the fuel areemptied, larger amounts of air tend to be drawn in and pumped with thefuel, rendering pumping difficult and resulting in inaccuratemeasurements of fuel. Thus, in certain embodiments, a system 310 isdisposed in line between a first fuel storage vessel 312 and the vesselto which the fuel is being pumped, namely a second fuel storage vessel314. While system 310 may be of many different configurations asdescribed herein, in certain preferred embodiments, system 310 includes,as shown in FIG. 12, a curvilinear flow path 316 in a flow shaping line317. Flow shaping line 317 includes a plurality of successive loops L ofsubstantially the same diameter, each loop L being substantiallyhorizontally disposed, thereby forming a “stack” of loops L. It has beenfound that in the case of loops L disposed substantially in thehorizontal, the diameters of the loops, i.e., the coil sizes, do notneed to be successively descending from the first end 364 of flowshaping line 317 to the second end 366 as is desirable in verticalorientation of the loops. Thus, fuel is removed from the first vessel312, passed through system 310 and then directed to the second vessel314. The fuel entering the first end 364 of flow shaping line 317 mayhave a large proportion of air included with the liquid fuel. The liquidfuel exiting the second end 366 of flow shaping line 317 has beensubstantially scrubbed of the entrained air.

Although illustrative embodiments of the invention have been shown anddescribed, a wide range of modification, changes and substitution iscontemplated in the foregoing disclosure. In some instances, somefeatures of the present invention may be employed without acorresponding use of the other features. Accordingly, it is appropriatethat the appended claims be construed broadly and in a manner consistentwith the scope of the invention.

What is claimed is:
 1. A fuel bunkering apparatus comprising; a firstfuel storage vessel having an outlet; a second fuel storage vesselhaving an inlet; a pipe having a first end in fluid communication withthe outlet of the first fuel storage vessel and a second end in fluidcommunication with the inlet of the second fuel storage vessel, the pipehaving a plurality of curvilinear pipe loops arranged adjacent oneanother along a substantially vertical axis extending from a first axisend to a second axis end in a vertically stacked arrangement; a loopoutlet port disposed along the pipe between the two ends; and a gasseparator in fluid communication with the loop outlet port, wherein eachpipe loop is characterized by a diameter and the diameters of at least aportion of the plurality of adjacent pipe loops are the same.
 2. Theapparatus of claim 1, wherein each of the loops is substantiallyhorizontal.
 3. The apparatus of claim 1, further comprising a liquidreturn line fluidly coupled between a liquid exit of the gas separatorand the pipe, a return junction formed between the liquid return lineand the pipe between the loop outlet port and the inlet of the secondfuel storage vessel.
 4. The apparatus of claim 1, further comprising arestriction in the pipe between the loop outlet port and the returnjunction.
 5. The apparatus of claim 1, wherein at least one of the firstfuel storage vessel and the second fuel storage vessel comprises abunkering barge.
 6. The fuel bunkering apparatus of claim 1, furthercomprising at least three pipe loops adjacent one another and having thesame diameter.
 7. The fuel bunkering apparatus of claim 1, furthercomprising at least four curvilinear pipe loops adjacent one another ina vertically stacked arrangement.
 8. A fuel bunkering method,comprising: delivering a bunker fuel in a first fuel storage tank to asecond fuel storage tank; directing the bunker fuel from the first fuelstorage tank to enter into a first end of a flow shaping line, through aplurality of curvilinear pipe loops defined in a portion of the flowshaping line arranged adjacent one another along a substantiallyvertical axis extending from a first axis end to a second axis end, andto exit out of the flow shaping line through a second end of the flowshaping line in fluid communication with the second fuel storage tank;utilizing the flow shaping loops to separate a gas from the bunker fuelalong a portion of the wall of the plurality of curvilinear pipe loopsdefined in the flow shaping line; and diverting the separated gas fromthe flow shaping line to a gas separator through a loop outlet portdisposed along the flow shaping line downstream of the first end andupstream of the second end.
 9. The fuel bunkering method of claim 8,further comprising pumping the bunker fuel from the first fuel storagetank to the second fuel storage tank through the flow shaping line. 10.The fuel bunkering method of claim 9, wherein pumping the bunker fuelcomprises drawing in air from the first storage tank as the firststorage tank is emptied, and wherein separating the gas from the bunkerfuel further comprises separating the air pumped from the first fuelstorage tank with the bunker fuel.
 11. The fuel bunkering method ofclaim 8, further comprising measuring a property of the bunker fuelwithin the flow shaping line.
 12. The fuel bunkering method of claim 8,further comprising returning a liquid from the gas separator to the flowshaping line downstream of the loop outlet port.
 13. The fuel bunkeringmethod of claim 12, further comprising restricting the liquid from thebunker fuel between the loop outlet port and the second end of the flowshaping line to thereby accelerate the liquid from the gas separator.14. The fuel bunkering method of claim 8, wherein directing the bunkerfuel through a plurality of curvilinear pipe loops comprises directingthe fluid in a generally vertical downward direction.
 15. The fuelbunkering method of claim 8, wherein directing the bunker fuel throughplurality of pipe loops comprises directing the bunker fuel through atleast one pipe loop having substantially the same as the diameter of atleast another adjacent pipe loop.
 16. The fuel bunkering method of claim8, further comprising coupling the flow shaping line between the firstfuel storage tank and the second fuel storage tank and supplying a shipwith fuel from the second fuel storage tank.
 17. An apparatus forseparating gas from liquid in a gas-liquid flow, said apparatuscomprising: a first pipe having a first end and a second end, said pipecomprising a plurality of curvilinear pipe loops arranged adjacent oneanother along a substantially vertical axis extending from a first axisend to a second axis end, at least a portion of which plurality ofcurvilinear pipe loops are of the same diameter and said pipe loops areadjacent one another in a vertically stacked arrangement wherein eachloop is substantially horizontal; an outlet port disposed along thefirst pipe between the two ends of the first pipe, said outlet portdefining a junction between said first pipe and a separator inlet line,wherein said separator inlet line is connected to said outlet port; andsaid apparatus further comprising a gas separator in fluid communicationwith said outlet port through said separator inlet line such that fluidis capable of flowing into said gas separator through said separatorinlet line.
 18. The apparatus of claim 17, further comprising at leastfour curvilinear pipe loops adjacent one another in a vertically stackedarrangement.
 19. The apparatus of claim 17, further comprising a firstfuel storage vessel having an outlet; a second fuel storage vesselhaving an inlet; wherein the first end of the pipe is in fluidcommunication with the outlet of the first fuel storage vessel and thesecond end of the pipe is in fluid communication with the inlet of thesecond fuel storage vessel.
 20. The apparatus of claim 19, wherein eachof the loops is substantially horizontal.
 21. The apparatus of claim 19,further comprising a liquid return line fluidly coupled between a liquidexit of the gas separator and the pipe, a return junction formed betweenthe liquid return line and the pipe between the loop outlet port and theinlet of the second fuel storage vessel.
 22. The apparatus of claim 20,further comprising a restriction in the pipe between the loop outletport and the return junction.
 23. The apparatus of claim 19, wherein atleast one of the first fuel storage vessel and the second fuel storagevessel comprises a bunkering barge.
 24. A method for separating gas fromliquid in a gas-liquid flow, the method comprising: delivering a liquidin a first storage tank to a second storage tank; directing the liquidfrom the first storage tank to enter into a first end of a flow shapingline, through a plurality of curvilinear pipe loops defined in a portionof the flow shaping line arranged adjacent one another along asubstantially vertical axis extending from a first axis end to a secondaxis end, and to exit out of the flow shaping line through a second endof the flow shaping line in fluid communication with the second storagetank; utilizing the flow shaping loops to separate a gas from the liquidalong a portion of the wall of the plurality of curvilinear pipe loopsdefined in the flow shaping line; and diverting the separated gas fromthe flow shaping line to a gas separator through a loop outlet portdisposed along the flow shaping line downstream of the first end andupstream of the second end.
 25. The method of claim 24, furthercomprising pumping the liquid from the first storage tank to the secondstorage tank through the flow shaping line.
 26. The method of claim 25,wherein pumping the liquid comprises drawing in air from the firststorage tank as the first storage tank is emptied, and whereinseparating the gas from the liquid further comprises separating the airpumped from the first storage tank with the liquid.
 27. The method ofclaim 24, further comprising measuring a property of the liquid withinthe flow shaping line.
 28. The method of claim 24, further comprisingreturning a liquid from the gas separator to the flow shaping linedownstream of the loop outlet port.
 29. The method of claim 24, whereindirecting the liquid through a plurality of curvilinear pipe loopscomprises directing the liquid in a generally vertical downwarddirection.
 30. The method of claim 24, wherein directing the liquidthrough plurality of pipe loops comprises directing the liquid throughat least one pipe loop having substantially the same diameter as thediameter of at least another adjacent pipe loop.
 31. The method of claim24, further comprising coupling the flow shaping line between the firststorage tank and the second storage tank and supplying a ship with theliquid from the second storage tank.